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arXiv:0705.1996v2 [quant-ph] 15 May 2007 Critique of “Quantum Enigma: Physics encounters Consciousness” Michael Nauenberg Department of Physics University of California, Santa Cruz, CA 95064 Abstract The central claim that understanding quantum mechanics requires a conscious observer, which is made made by B. Rosenblum and F. Kuttner in their book ”Quantum Enigma: Physics encounters con- sciousnes”, is shown to be based on various misunderstandings and distortions of the foundations of quantum mechanics. Introduction When discussing the quantum theory and its interpretation in physics, Bohr often emphazised the importance of describing fully the experimental appa- ratus. Part of such a description consists of selecting the proper words to describe the observations. In 1948 he put it as follows [1]: Phrases often found in the physical literature as ‘disturbance of phenomena by observation’ or ‘creation of physical attributes of objects by measurements’ represent a use of words like ‘phenom- ena’ and ‘observation’ as well as ‘attribute’ and ‘measurement’ which is hardly compatible with common usage and practical definition and, therefore, is apt to cause confusion. As a more appropriate way of expression, one may strongly advocate limi- tation of the use of the word phenomenon to refer exclusively to observations obtained under specified circumstances, including an account of the whole experiment. 1

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Page 1: arXiv:0705.1996v2 [quant-ph] 15 May 2007 · arXiv:0705.1996v2 [quant-ph] 15 May 2007 Critiqueof“Quantum Enigma: Physics encounters Consciousness” Michael Nauenberg Department

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007 Critique of “Quantum Enigma: Physics

encounters Consciousness”

Michael NauenbergDepartment of Physics

University of California, Santa Cruz, CA 95064

Abstract

The central claim that understanding quantum mechanics requiresa conscious observer, which is made made by B. Rosenblum and F.Kuttner in their book ”Quantum Enigma: Physics encounters con-sciousnes”, is shown to be based on various misunderstandings anddistortions of the foundations of quantum mechanics.

Introduction

When discussing the quantum theory and its interpretation in physics, Bohroften emphazised the importance of describing fully the experimental appa-ratus. Part of such a description consists of selecting the proper words todescribe the observations. In 1948 he put it as follows [1]:

Phrases often found in the physical literature as ‘disturbance ofphenomena by observation’ or ‘creation of physical attributes ofobjects by measurements’ represent a use of words like ‘phenom-ena’ and ‘observation’ as well as ‘attribute’ and ‘measurement’which is hardly compatible with common usage and practicaldefinition and, therefore, is apt to cause confusion. As a moreappropriate way of expression, one may strongly advocate limi-tation of the use of the word phenomenon to refer exclusively toobservations obtained under specified circumstances, including anaccount of the whole experiment.

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Unfortunately, these admonitions are generally ignored by the authors ofQuantum Enigma (QE) [2], and as a consequence this book will cause plentyof the confusion predicted by Bohr. In the following section, I will quoteselected paragraphs that contain what I consider to be some of the more out-landish statements which I found in this book, followed by my critique. Insupport of this critique, I include in the last section some relevant quotationsfrom Einstein, Bohr, Heisenberg, and Schrodinger, who laid the foundationsof modern quantum theory, and by some other prominent contemporaryphysicists, concerning quantum mechanics and the measurement process.These quotations contradict many of the claims and unsupported assertionsmade in this book about the interpretation of quantum theory. In particu-lar, all these physicists deny the supposed role of consciousness in physics,for which there isn’t any experimental support whatsoever. But the claimthat consciousness plays a role in quantum mechanics (“our bias,” as theauthors write) is the underlying message which the authors of QE would liketo implant on their readers.

The authors of QE also offer quotations from prominent scientist in sup-port for their claims. For example, Martin Rees, the Astronomer Royal andcurrent president of the Royal Society in London, is quoted as saying (ref.[2] page 193):

In the beginning there were only probabilities. The universe couldonly come into existence if someone observed it. It does notmatter that the observers turned up several million years later.The universe exists because we are aware of it.1 (ref. [2] page193).

1The authors of QE do not give sources for the numerous quotations in their book.Therefore, I asked Martin Rees where he had made this statement and he responded: “Iam perplexed by the quote. It seems rather ’Wheelerish’ – not at all the sort of thing Iwould have said.” Apparently this quotation was inserted by an editor as a caption to afigure in an article that Rees had written for the New Scientist (August 6, 1987). Indeed, itturns out that this figure is a copy of a drawing made by John Wheeler which also appearson page 200 of QE, and that the caption paraphrases Wheeler’s words in a script entitled“Law without law.” The original caption starts with “The universe viewed as a self-excitedcircuit.” Apparently, Wheeler was in a playful mood, because he remarked “caution:consciousness has nothing whatsoever to do with quantum processes” (see quotation atthe end of the next section)

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In contrast, however, Murray Gell-Mann, the winner of a Nobel Prize forhis fundamental contributions to particle physics, is quoted in QE as sayingthat

The universe presumably couldn’t care less whether human beingsevolved on some obscure planet to study its history; it goes onobeying the quantum mechanical laws of physics irrespective ofobservation by physicists (ref. [2] p.156)

The authors’ response is that “in talking about classical physics, Gell-Mann’s presumption [my emphasis] would go without saying (ref. [2] p.168). But Gell-Mann is talking about quantum mechanics which governs allthe fundamental process in our the universe. The authors’ distinction herebetween classical and quantum mechanics is a red herring. The examplesdiscussed in QE are concerned with elementary or single quantum processes.Evidently, the authors are unaware that there is a distinction between an-alyzing such processes and the multiple quantum processes that occur inmacroscopic systems like living creatures, stars, and galaxies.2

In fact, it is the statement made by Gell-Mann and not the one attributedincorrectly to Rees (see footnote 1), that represents the generally acceptedview that all processes in the universe evolve in accordance with the laws ofquantum mechanics without any need whatsoever of conscious observers. Incases where classical mechanics is adequate to explain the observations, it isregarded as an approximate theory.

John Bell, who is regarded as having made some of the most significantmodern contributions to our understanding of quantum theory, remarkedthat

2For example, consider the evolution of a star like the sun. This evolution is primarilybased on quantum phenomena, with classical gravitational forces primarily providing theconfinement for the atomic process. Thus, the production of energy is due to nuclearreactions governed by quantum processes in the interior of the star, which requires alsothe phenomenom of quantum tunneling, the emission of radiation, which is governed by thelaws of quantum field theory, and the eventual collapse of a star like the sun into a whitedwarf or neutron star, which depends on the quantum mechanical degeneracy pressureof electrons or neutrons [3]. Even the explosion of more massive stars into supernovasgives rise to quantum nuclear processes leading to the emission of neutrinos. Since thestart of the Big Bang all these processes have been going on without the need of any“observers,” conscious or otherwise. The most striking evidence of the Big Bang is thelow-temperature black-body radiation which was created in the early universe by quantumprocesses, obviously without any observers around [4]

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I see no evidence that it is so [that the cosmos depends on ourbeing here to observe the observables] in the success of contem-porary quantum theory. So I think it is not right [my emphasis]to tell the public that a central role for conscious mind is inte-grated into modern atomic physics. Or that ‘information’ is thereal stuff of physical theory [5]

I think the experimental facts which are usually offered to showthat we must bring the observer into quantum theory do notcompel us to adopt that conclusion. [6]

For a long time I have argued along the same lines that I found recently inan article by A. Leggett [7], a Nobel prize winner who has given considerablethought to the quantum measurement paradox,

...it may be somewhat dangerous to ‘explain’ something one doesnot understand very well [the quantum measurement process] byinvoking something [consciousness] one does not understand atall!

But instead of “it may be dangerous,”, I would say “it is nonsense.”These last three comments firmly contradict the central claims of the

authors of QE concerning a supposed role for consciousness in physics .3

Critique of selected quotations from QE

Each of the quotations from QE listed below is written in typewriter style,and its location in QE is identified by the page number (p) and the linenumber counted either from the bottom (b) or the top (t) of the page. Mycriticisms follow after each of these quotations.

3I share Steve Hawking’s impulse “to reach for my gun” (ref. [2], p. 120) wheneverSchrodinger’s cat story is told. This cat story is notorious. It requires one to accept thata cat, which can be in innumerable different states, can be represented by a two-statewavefunction, a bit of nonsense which Schrodinger himself originated. However, a moviecamera installed in the box containing the cat would record a cat that is alive until theunpredictable moment that the radioactive nucleus decays opening the bottle containingcyanide thus killing the cat. It is claimed that Schrodinger never accepted the statisticalsignificance of his celebrated wavefunction.

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This is a controversial book. But nothing we say about

quantum mechanics is controversial. The experimental results

we report and our explanation of them with quantum theory

are completely undisputed (p.3 t.1)

Invariably, however, experimental results are reported in this book in a verysketchy and innacurate manner, which leads to the confusion predicted byBohr (see Introduction). Moreover, as will be shown below, the statementthat “our explanation of them [the experiments] with quantum theory isundisputed” usually turns out to be false.

That physics has encountered consciousness cannot be denied

(p.4 b.13)

Presumably Bohr, Heisenberg, Einstein, and many other great physicists Iquote in this critique have been living in denial. Only very few prominentphysicists, e.g. E. Wigner, have argued for a role of consciousness in themeasurement process. But such exceptional cases do not justify ignoring thewarning of Bell “that it is not right to tell the public that a central role forconsciousness is integrated into modern physics”

The quantum enigma, conventionally called the ‘‘measurement

problem,’’ appears right up front in the simplest quantum

experiment. (p.5 t.9)

The measurement problem can be summarized as the question why macro-scopic detectors like a Geiger counter or a photographic plate, which areultimately made of atoms, are never found in a superposition of quantumstates. The authors of QE claim that consciousness is what destroys thissuperposition. But if there are several observers, whose consciousness is re-sponsible for this collapse of superposition? If both authors of QE look at thesame time at a photographic film recording an atomic event, who “caused”the collapse of superposition? And what happens when you have a thousandobservers, as is often the case in current high-energy physics when oftenbillions of events are observed?

Try summarizing the implications of quantum theory, and

what you get sounds mystical... To account for the demonstrated

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facts, quantum theory tells us that an observation of one

object can instantaneously influence the behaviour of another

greatly distant object---even if no physical force connects

the two. Einstein rejected such influences as ‘‘spooky

interactions,’’ but they have now been demonstrated to

exist. (p.12 b.14)

The “facts” that have been demonstrated are correlations between dis-tant particles which are predicted according to quantum mechanics as a con-sequence of conservation laws. For example, due to conservation of energyand momentum in a two particle scattering event, the observation of themomentum of one of the scattered particles determines the momentum ofthe other scattered particle if the initial state is known. This correlationis expected both in classical and in quantum theory, and there is nothing“mystical” about it. There are also correlations of polarizations of entangledphotons which are predicted by quantum theory that have been confirmedby experimental observation. These correlations are consequences of the con-servation law of angular momentum. The claim that Einstein rejected thesecorrelations is false (for some quotations of his views of quantum theory seesection II).

For example, according to quantum theory, an object can

be in two or many places at once---even far distant places.

Its existence at the particular place it happens to be

found becomes an actuality upon its (conscious) observation.

(p.7 b.9)

Both statements are false. Quantum theory is a theory that predicts theprobability of observing physical attributes of a particle, such as position andmomentum. The probability of finding a particle in “two places at once” isalways zero. The question can be asked as to where a particle is located inbetween observations, but this question is metaphysical, and lies outside therealm of scientific inquiry. The claim that it requires consciousness to makethe location of an object an “actuality,” which is repeated like a mantrathroughtout QE, is not supported by any evidence, and it is demonstrablyfalse.

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But they [our physics collegues] will find nothing sci-

entifically wrong with what we say. The physics facts we

present are undisputed. (p.13 b.12)

This claim, which is being promoted in QE to an unsuspecting public, isuntrue, as will be demonstrated here in many examples.

The waviness4 in a region is the probability of finding the

object in that region. Be careful---the waviness is not

the probability of the object being there. There is a

crucial difference! The object was not there until you

found it there. Your happening to find it there caused

it to be there. This is tricky and the essence of the

quantum enigma. (p.75 b.12)

The muddled second half of this statement is incorrect. The absolutesquare of the wave function gives the probability for the outcome of an ex-perimental observation such as the localization of an atomic particle. A par-ticle can be localized by an appropriate recording device, a Geiger counter, aphotographic plate, etc., independent of any particular human observer. Oneneed only to realize that different observers who examine such a recordingall reach the same conclusion about the region of localization to see that theremark “your happening to find it there caused it to be there” is nonsense.An observer does not cause the occurence of an atomic event. This is like be-lieving that you can bend spoons with your mind. No one has given evidencefor such effects.

The authors of QE claim that

In quantum theory there is no atom in addition to the wavefunction

of the atom. This is so crucial that we say it again in

other words. The atom’s wave-functions and the atom are

the same thing; ‘‘the wave function of the atom’’ is a

synonym for ‘‘the atom.’’ (p.77 t.6)

Since the wavefunction is synonymous with the atom itself,

the atom is simultaneously in both boxes. The point of

4This name was introduced by Bell, and refers to the absolute square of thewavefunction

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that last paragraph is hard to accept. That is why we

keep repeating it. (p.103 t.3)

In other words, since matter consist of atoms, presumably while reading thisnonsense you are sitting on a chair made up of wavefunctions (do you also feelthe vibrations?). Of course, the wavefunction of an atom is not a synonym(having the same meaning) for the atom. The claim for such a synonym isnonsense. Atoms have mass, charge, total spin, and energy levels, which areinvariant properties, while the wavefunction describes the evolution of itsdynamical variables. According to quantum theory, the square of the wavefunction gives the probability that the measurement process yields allowedvalues for a set of commuting variables. For this purpose it is necessary tostudy an ensemble of atoms which initially are prepared under identicallythe same physical conditions. This is fundamentally different from claimingthat the wavefunction is synonymous with the atom itself. The probabilityof observing an atom simultaneously at two different locations, by an actualmeasurement, is always zero. Hence, it is false to claim that the atom “issimultaneously in both boxes.”

Accordingly, before a look collapses a widely spread-out

wavefunction to the particular place where the atom is

found, the atom did not exist there prior to the look.

The look brought about the atom’s existence at that particular

place---for everyone. (p.77 t.9)

This is a powerful “look” indeed, but again, this is false. In spite of Bohr’srepeated warning of the importance of carefully choosing appropriate lan-guage to describe the observation of atomic events, this warning is againignored here. Statements like “before a look collapses ... a wavefunction” or“the look brought about...the atom’s existence” do not make any sense orhave any meaning whatsoever. According to the description of some of thefounders of the quantum theory who are quoted in the next section, a mean-ingful statement is that the reduction or collapse of a wavefunction occursafter a recording has been made by an irreversible amplification of an atomicevent by a macroscopic detector, like a Geiger counter or a photographicplate. The combination of eye lens, retina, optical nerve and neural memorycells can be regarded as a detector for the special case of photons in a visiblefrequency range, but such a detector is unique to a single observer.

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The most accurate way of describing the state of the unobserved

atom is to put into English the mathematics describing

the state of the atom before we looked to see where it

is: The atom was simultaneously in two states: in the first

state, it is in-the-top-box-and-not-in-the-bottom-box,

and simultaneously in the second state it is in-the-bottom-box-and-not-in-the-top-box.

(p.79 t.15)

This so called “accurate” description is actually pure metaphysics, since it isnot possible to established the location of an “unobserved” atom. Accordingto quantum theory, before an observation is made there is only a probability offinding the atom in either the top or the bottom box. The essence of quantumphysics is that nothing definite can be said about the location of the atombefore a measurement of it is made. For example, we can send a beam ofphotons into a box and detect the scattered photons. This can establishapproximately the localization of the atom at the time of the interaction ofthe photon and the atom, but not at any time before this interaction tookplace.

The talk we offer in a quantum mechanics class for physics

students is that when we look in a box and find no atom,

we instantaneously collapse the atom’s waviness [wavefunction]

into the other box. (p.108 t.11)

The statement refers to the possibility that even though a detector is nottriggered the wavefunction of the system is changed. This appears to con-tradict the requirement that the detector must make a recording to alter thewavefunction of the system. In fact, the presence of a detector to determine,for example, the location of an atom, also alters the evolution of the wave-function, and consequently the probabilities of various outcomes. Therefore,if a detector is not triggered, there is a finite probability that the atom didnot take the path crossing the detector. But there is also a non-vanishingprobability that the atom crossed the detector without triggering it. There-fore, it can not be concluded with certainty in what box the atom is locateduntil a second detector triggers and determines its location. Certainly con-

sciousness, i.e. “ we look in a box and find no atom, we instanteniouslycollapse the atom’s waviness ...” , has nothing whatsoever to do with theexplanation of this subtle property of quantum mechanics.

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But randomness was not Einstein’s most serious problem

with quantum mechanics. What disturbed Einstein , and

more people today, is quantum mechanics’ apparent denial

of ordinary physical reality---or, maybe the same thing,

the need to include the observer in the physical description---an

intrusion of consciousness into the physical world. (p.80t.8)

While Einstein was concerned with the nature of physical reality, it is highlymisleading to indicate that it is the “same thing” to imply that he was con-cerned with the “intrusion of consciousness into the physical world.” On thecontrary, he made it clear that the generally accepted statistical interpreta-tion of the wavefunction is an “objective description” whose concepts clearlymake sense independently of the observation and the observer (see the nextsection for the full quotation in his letter to Born a year before his death).

John Bell felt that the quantum mechanical description

will be superseded... It carries in itself the seeds of

its own destruction... He feels that ‘‘the new way of

seeing things will involve an imaginative leap that will

astonish us.’’ (p.87 t.5)

The authors of QE fail to point out that this quotation appeared in an articlewritten jointly by Bell and myself about 40 years ago [15]. But neither ofthem bothered to ask for my current views on this subject. I will take thiopportunity to make a disclaimer here. In our paper we also said, tongue incheek, that

The experiment may be said to start with the printed proposaland to end with the issue of the report. The laboratory, theexperimenter, the administration, and the editorial staff of thePhysical Review are all just part of the instrumentation. The in-corporation of (presumably) conscious experimenters and editorsinto the equipment raises a very intriguing question... If the in-terference is destroyed, then the Schrodinger equation equation isincorrect for systems containing consciousness. If the interferenceis not destroyed, the quantum mechanical description is revealedas not wrong but certainly incomplete.

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In a footnote we added that “we emphasize not only that our view is thatof a minority but also that current interest in such questions is small. Thetypical physicist feels that they have been long answered, and that he willfully understand just how if ever he can spare twenty minutes to think aboutit.” (As a graduate student, one of the authors, Bruce Rosenblum, reportsthat he “assumed that if I spent an hour or so thinking it [the wave particleduality] through, I’d see it all clearly” ( ref. [2], p. 10).)

At the time that we made these comments, I did not understand thata Geiger counter, a photographic film, the retina of the eye and associatedneural connections. or any other detector creates a more or less permanentrecord by means of physical and/or chemical processes that are irreversible.As in thermodynamics, such processes involve a very large number of atomswhich are involved through an amplification process essential to the creationof a recording.5

A major failure of QE is that this essential feature of the measurementprocess in quantum theory is not even mentioned. It is worth rememberingthat irreversibility already was a conundrum for classical physics because thebasic equations are time reversal invariant. The same invariance applies tothe basic equations in quantum mechanics. The emergence of irreversibil-ity occurs in systems with large number of particles, which is the case withrecording devices, and constitutes the foundations of statistical thermody-namics [4].

There is no official Copenhagen interpretation. But every

version grabs the bull by the horns and asserts that an

observation produces the property observed. (p.100 t.11)

Read, for example, the quotations of Bohr, Heisenberg, Einstein and oth-ers quoted here and in the next section to see that none of them ever made

5Following Bohr’s admonition to discuss the details of the measuring apparatus, wenote that a typical photographic film consist of an irregular array of silver bromide ioniccrystals suspended on an emulsion. The absorption of a photon ejects an electron whichgives rise to a catalytic reaction where a very large number of silver ions transform intosilver atoms. After the film is processed these silver atoms give rise to a spot whichabsorbs visible light shining on it, thus producing a dark spot which approximately marksthe position on the screen where the photon had landed. The cascade of silver ions intosilver atoms produced by the photon is the amplification which which gives rise to anirreversible process, and therefore it can not be described by the evolution of a simplewavefunction.

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such a nonsensical statement as “produces the property observed” when re-ferring to an observation.

Even students completing a course in quantum mechanics,

when asked what the wavefunction tells, often incorrectly

respond that it gives the probability where the object

is. (p.103 t.7)

Actually, the students’ response is essentially correct if it is somewhat mod-ified by stating that “it is the probability where the object will be found ”in an experiment designed to establish the position of the object.

Our concern is with the consciousness central to the quantum

enigma---the awareness that appears to affect physical

phenomena. Our simple example was that your observation

of an object wholly in a single box caused it to be there,

because you presumably could have chosen to cause an interference

pattern establishing a contradictory situation, whereby

the object would have been a wave simultaneously in two

boxes. (p.168 t.18)

It is hard to imagine that more nonsense about the meaning of quantumtheory could be encapsulated into a single sentence. To begin with, an ex-perimental set up to observe in which of two boxes an atom is located does not“cause” such a localization. Instead, an observer who examines the outputof a recording finds the location of the atom in accordance with a probabilitydistribution given by the absolute square of Schrodinger’s ψ function appro-priate to the experimental arrangement. A different experimental setup maylead to observations of interference patterns by coherent atomic beams, butthese patterns are not “caused” by the “awareness” of the observer. Theinterference patterns can be recorded on a photographic film and seen thereby anyone examining this film. It is completely ridiculous to propose thatsomeone who sees the interference pattern on the film “caused” it to be there.The claim that by “choosing” the experimental set up the observer “caused”a particular outcome is a bizarre use of the word “cause” which has nothingwhatsoever to do with quantum theory. Bohr must be turning over in hisgrave.

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According to the authors of QE, consciousness is supposed to enter intoquantum theory because the observer can choose (“free will”) the experimen-tal setup, which demonstrates in this case complementary aspects, wave orparticle behaviour, of a photon, electron or other atomic objects. But thechoice of experiment can also be made, for example, by flipping a coin.

Does such a demonstration necessarily require a conscious

observer? Couldn’t a conscious robot, or even a Geiger

counter, do the observing? That most commonly voiced objection

to consciousness being required comes up---and is refuted---in

our next chapter. For now, just recall that, according

to quantum theory, if that robot or Geiger counter were

not in contact with the rest of the world it would merely

entangle to become part of a total superposition state---as

did Schrodinger’s cat. In that sense it would not truly

observe (p.168 b.12)

The operation of a Geiger counter is well understood, and it satisfies thecondition necessary to establish an observation, namely the irreversible am-plification of an atomic signal to create a semi-permanent record of an atomicevent. The only important contact of a Geiger counter to the “rest of theworld” is a power cable, which has to be plugged into a wall socket from whichelectricity flows from a power plant. A battery would also be sufficient.

Classical physics, Newtonian physics, is completely deterministic.

An ‘‘all-seeing eye,’’ knowing the situation of the universe

at one time, can know its entire future. If classical

physics applied to everything, there would be no place

for free will. (p.169 t.11)

This familiar quotation, due to Pierre Simon Laplace in the 18th century,was later shown to be false by Henri Poincare. Laplace was not aware thatNewtonian mechanics could lead to chaotic motion, and that in practiceclassical theory also is not deterministic, because of “sensitivity to initialconditions.”6. The implication that quantum mechanics is somehow essential

6Doubters should play with the double pendulum in the entrance of our physics dept.,which I had built by our mechanics shop to demonstrate chaotic dynamics.

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to free will, which is supported by some philosophers of science, is not valid.7

The Encounter “Officially” Proclaimed (p.180 t.1)

In his rigorous 1932 treatment ‘‘The Mathematical Foundations

of Quantum Mechanics,’’ John von Neumann showed that quantum

theory makes physics encounter with consciousness inevitable

[my emphasis] (p.180 t.1)

But in the next sentence, one finds that this “inevitable encounter” occursbecause von Neumann has treated a Geiger counter by a trivial wavefunctionconsisting of the superposition of only two states: whether it is in a “fired” orin an “unfired” state. This model of a Geiger counter, however, is incorrect,because it does not describe the essential property of such a detector, whichis to be able to make a permanent record of an atomic event. Such a recordingrequires an irreversible process.

You’re prompted to investigate how the robot chose which

experiment to do in each case. Suppose that you find that

it flipped a coin. Heads it did the-look-in-the-box experiment;

tails the interference experiment. You find something

puzzling about this: The coin’s landing seems inexplicably

connected with what was presumably in a particular box-pair

set. Unless ours ia a strangely deterministic world, one

that conspired to correlate the coin landing with what

was in the box pairs, there is no physical mechanism for

that correlation. (p.183 b.15)

The outlandish notion that there exists a correlation between the “coin land-ing” and the outcome of an experiment is tied to the previous bizarre claimthat an observer can “cause” this outcome. This is the consequence of thesloppy language which Bohr had warned should be avoided.

7Some time ago I had an argument about this issue with the Berkeley philosopher JohnSearle. However, he did not seem to be aware that the noise due to finite temperaturethermal fluctuations in the firing of neural brain cells is more important than the zero-temperature quantum fluctuations or effects of the uncertainty principle.

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You therefore replace the robot’s coin flipping by the

one decision mechanism you are sure is not connected with

what supposedly exists in a particular box-pair set: your

own free choice. You push a botton telling the robot which

experiment to do with each box-pair set. You now find

that by your conscious free choice of experiment you can

prove either that the objects were concentrated or that

they were distributed. You can choose to prove either

of two contradictory things. You are faced with the quantum

enigma, and consciousnes is involved. (p.183 b.8)

If you have had the patience to come this far, you finally will have found outhow, according to the authors of QE, physics encounters consciousness: byreplacing the decision making of a robot who flips coins with the free will of aconscious observer. This claim, however, does not make any sense, because asa “conscious observer” you can also make decisions based on flipping coinsrather than on your free will. Following the logic of the authors of QE,you would have to conclude that physics encounters coin flipping. It shouldbe pointed out that while a few eminent physicists such as Eugene Wignerbelieve that consciousness plays a role in the collapse of the wavefunction, hedid not argue that this role has anything to do with “free will”. This is a newand unsubstantiated twist to the role of consciousnes given by the authorsof QE. Such a bias should not be foisted on the general public as a generallyaccepted notion in modern physics.8

8It is easy to demonstrate that the persistent claim of the authors of QE that it isnecessary to choose or flip a coin to decide which of their two gedanken experimentsshould be performed can be avoided by performing both experiments at the same time.Light of appropriate frequency and variable intensity is shined on the two slits throughwhich individual atoms of fixed momentum are directed. Then a scattered photon and anappropriate detector can record through which slit an atom passed, while a photographicplate can record the position where the atom lands later on. All the spots that arerecorded on the photographic plate are then separated into two classes of events: a)events where a scattered photon is detected and b) events where no scattered photon isdetected. According to quantum theory, events of class b) show an interference patterncharacteristic of the two slit experiment although it is modified by the presence of theradiation field. Events of class a), however, do not show this interference pattern. Thefraction of the events in class a) and b) depends on the intensity of the light shiningon the two slits: the weaker the intensity the greater the number of events in class a)and viceversa. It is assumed here that the detector of scattered photons is very efficient,

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If we consider the robot argument from the viewpoint of

quantum theory, the isolated robot is a quantum system,

and von Neumann’s conclusion applies: the robot entangles

with the object in the box pairs, and the object’s wavefunction

does not collapse into a single box until a conscious observer

views the robot’s printout. (p.184 t.1)

The notion that the the “robot entangles with the object,” implying that therobot, or for that matter any macroscopic measuring apparatus like a Geigercounter or a photographic film, can be represented by a wavefunction ψ isincorrect. The essential property of macroscopic systems like robots is thatthese systems are able to create a record of an atomic event by a mechanism ofamplification which is irreversible. This mechanism has nothing whatsoeverto do with consciousness.

In conclusion, I like to quote John Wheeler [14]

Caution: “Consciousness” has nothing whatsover to do with thequantum process. We are dealing with an event that makes it-self known by an irreversible act of amplification, by an indeliblerecord, an act of registration. Does that record subsequently en-ter into the “consciousness” of some person, some animal or somecomputer? Is that the first step into translating the measurementinto “meaning”—meaning regarded as “the joint product of allthe evidence that is available to those who communicate.” Thenthat is a separate part of the story, important but not to be con-fused with “quantum phenomena.”

This quotation appears in QE, p. 165, but in a truncated form. Whatis left out is Wheeler’s definition for the word meaning. The authors of QEcomment to Wheeler’s remark

We take this as an injunction to physicists (as physicists)

to study only the quantum phenomena, not the meaning of

the phenomena.

otherwise the interference pattern will be further smeared out, because it contains alsoevents where a scattered photon from an atom was not detected. See also the descriptiongiven by R. Feynman in reference [16] [17]

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But Wheeler’s injunction clearly is against claiming that consciousness hassomething to do with quantum phenomena, which is the central theme ofQE. It is not an injunction against studying the cognitive processes in thebrain associated with consciousness, which are “a separate part of the story,important but not to be confused with quantum phenomena.”

Remarks on the quantum measurement process by some

of the founders of the quantum theory, and by promi-nent contemporary physicists

Below, I have included some quotations on quantum measurement and therole of the observer by the founders of quantum theory and some prominentcontemporary physicists, which are relevant to my critique of QE.

N. Bohr (1958)

Far from involving any special intricacy, the irreversible amplifi-cation effects which the recording of the presence of atomic ob-jects rests rather reminds of the essential irreversibility inherentin the very concept of observation. The description of atomicphenomena has in these respects a perfectly objective [my em-phasis] character, in the sense that no explicit reference is madeto any individual observer and that therefore, with proper regardto relativistic exigences, no ambiguity is involved in the commu-nication of information [8]

W. Heisenberg (1958)

The probability function does—unlike the common procedure inNewtonian mechanics—not describe a certain event but, at leastduring the process of observation, a whole ensemble [my empha-sis] of events...When the old adage “Natura non facit saltus”9 isused as a basis of criticism of quantum theory, we can reply thatcertainly our knowledge can change suddendly and that this factjustifies the use of the term “quantum jumps” [or collapse of thewavefunction].

9Nature does not act in jumps.

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Therefore, the transition from the “possible” to the “actual” takesplace during the act of observation. If we want to describe whathappens in an atomic event, we have to realize that the word”happens” can apply only to the observation, not to the stateof affairs between two observations. It applies to the physical,not the psychical [my emphasis] act of observation, and we maysay that the transition from the “possible” to the “actual” takesplace as soon as the interaction of the object with the measuringdevice, and therefore with the rest of the world, has come intoplay; it is not connected with the act of registration of the resultby the mind [my emphasis] of the observer. The discontinuouschange in the probability function [collapse of the wavefunction],however, takes place with the act of registration, because it isthe discontinuous change of our knowledge in the instant of reg-istration that has its image in the discontinuous change of theprobability function. ...Certainly quantum theory does not con-tain genuine subjective features, it does not introduce the mind[my emphasis] of the physicist as a part of the atomic event [9].

A. Einstein (1949)

One arrives at very implausible theoretical conceptions, if oneattempts to maintain the thesis that the statistical quantum the-ory is in principle capable of producing a complete descriptionof an individual [my emphasis] physical system. On the otherhand, those difficulties of theoretical interpretation disappear, ifone views the quantum mechanical description as the descriptionof ensembles of systems.

I reached this conclusion as the result of quite different types ofconsiderations. I am convinced that everyone who will take thetrouble to carry through such reflections conscientiously [my em-phasis] will find himself finally driven to this interpretation ofquantum-theoretical description (the ψ function is to be under-stood as the description not of a single system but of an ensembleof systems) [10]

A. Einstein (1953)

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All the same it is not difficult to regard the step into probabilis-tic quantum theory as final. One only has to assume that theψ function relates to an ensemble [my emphasis], and not to anindividual case... The interpretation of the ψ function as relatingto an ensemble also eliminates the paradox that a measurementcarried out in one part of space determines the kind of expecta-tion for a measurement carried out later in another part of space(coupling of parts of systems far apart in space) [11]

A. Einstein (1954)

The concept that the ψ function completely describes the physicalbehaviour of the individual single system is untenable 10 But one

10Einstein reached this conclusion by the following argument:

My assertion is this: the ψ function cannot be regarded as a complete de-scription of the system, only as an incomplete one. In other words: there areattributes of the individual system whose reality no on doubts but which thedescription by means of the ψ function does not include.

I have tried to demonstrate this with a system which contains one ‘macro-coordinate’ (coordinate of the centre of a sphere of 1 mm diameter). The ψfunction selected was that of fixed energy. This choice is permissible, becauseour question by its very nature must be answered so that the answer canclaim validity for every ψ function. From the considerations of this simplestcase, it follows that—apart from the existing macro-structure according to thequantum theory—at any arbitrarily chosen time, the centre of the sphere isjust as likely to be in one position (possible in accordance with the problem) asin any other. This means that the description by ψ function does not containanything which corresponds with a (quasi-) localization of the sphere at theselected time. The same applies to all systems where macro-coordinates canbe distinguished.

In order to be able to draw a conclusion from this as to the physical inter-pretation of the ψ function we can use a concept which can claim to be validindependently of the quantum theory and which is unlikely to be rejected byanyone: any system is at any time (quasi-) sharp in relation to its macro-coordinates. If this were not the case, an approximate description of the worldin macro-coordinates would obviously be impossible (’localization theorem’).I now make the following assertion: if the description by a ψ function could beregarded as the complete description of the physical condition of an individualsystem, one should be able to deduce the ‘localization theorem’ from the ψfunction and indeed from any ψ function belonging to a system which hasmacro-coordinates. It is obvious that this is not so for the specific example

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can well make the following claim: if one regards the ψ function asthe description of an ensemble it furnishes statements which—asfar as we can judge—correspond satisfactorily to those of clas-sical mechanics and at the same time account for the quantumstructure of reality. In this interpretation [Born’s statistical in-terpretation of quantum mechanics] the paradox of the apparentcoupling of spatially separated parts of systems also disappears.Furthermore, it has the advantage that the description thus in-terpreted is an objective description whose concepts clearly makesense independently of the observation and the observer [my em-phasis] [12]

R.P. Feynman (1963)

Nature does not know what you are looking at, and she behavesthe way she is going to behave whether you bother to take downthe data or not [16]

J. Wheeler (1986)

No elementary quantum phenomenon is a phenomenon until it’sbrought to a close by an irreversible act of amplification by adetection such as the click of a geiger counter or the blackeningof a a grain of photographic emulsion[13].

J. Bell (1986)

I think the experimental facts which are usually offered to showthat we must bring the observer into quantum theory do notcompel us to adopt that conclusion. [6]

The problem of measurement and the observer is the problemwhere the measurement begins and ends, and where the observerbegins and ends...there are problems like this all the way from the

which has been under consideration [12]

Stated in another way, the Schrodinger equation has solutions for ψ, such as a plane wave(fixed energy), which do not correspond to the description of the motion of any individualmacroscopic object like Einstein’s sphere which has also sharply localized position. Butthis solution does describe an ensemble of identical spheres which have centers distributeduniformly along the direction of motion, all moving with the same velocity.

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retina through the optic nerve to the brain and so on. I think,that—when you analyse this language that the physicists havefallen into, that physics is about the result of observation—youfind that on analysis it evaporates, and nothing very clear is beingsaid. [6]

N. van Kampen (1988)

Theorem IV. Whoever endows ψ with more meaning than isneeded for computing observable phenomena is responsible forthe consequences... [18]

References

[1] Quoted in A. Pais Subtle is the Lord... (Clarendon Press, New York1982) p. 455

[2] B. Rosenblum and F. Kuttner, Quantum Enigma, Physics Encounters

Consciousness (Oxford Univ. Press, 2006)

[3] M. Nauenberg and V.F. Weisskopf, “Why does the Sun shine,” Am.. J.Phys. 46, 23 (1978)

[4] M. Nauenberg, “The evolution of radiation towards thermal equilibrium:A soluble model which illustrates the foundations of statistical mechan-ics,” Am. J. Physics 72, 313 (2004)

[5] J.S. Bell, “Speakable and unspeakable in quantum mechanics,” Intro-ductory remarks at Naples–Amalfi meeting, May 7, 1984. Reprinted inJ.S. Bell, Speakable and Unspeakable in Quantum Mechanics (CambridgeUniv. Press 1987)

[6] P.C.W. Davies and J.R.Brown, Ghost in the Atom (Cambridge Univ.Press. 1986) Interview with J. Bell, pp. 47-48

[7] A. Leggett, “Reflections on the quantum measurement paradox,” inQuantum Implications, edited by ??? (Routledge, London 1991) p.94

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[8] N. Bohr, “Quantum Physics and Philosophy, Causality and Complemen-tarity” in Essays 1958–1962 on Atomic Physics and Human Knowledge

(Vintage Books, 1966)

[9] W. Heisenberg, Physics and Philosophy, The Revolution in Modern Sci-

ence (Prometheus Books, New York, 1999) p. 55

[10] Albert Einstein: Philosopher–Scientist

v.II, edited by P.S. Schilpp (Harper, New York 1949) p. 67

[11] A. Einstein in a letter to Max Born on Dec. 3, 1953. Reprinted in The

Born–Einstein letters 1916–1955, translated into English by Irene Born(Macmillan Press, China 2005) p. 204

[12] A. Einstein, Unpublished commentary sent in a letter to Max Born on12 January 1954. Reprinted in The Born–Einstein Letters 1916–1955,translated into English by Irene Born (Macmillan Press, China 2005)pp. 210-211

[13] P.C.W. Davies and J.R.Brown, interview with J.A. Wheeler, p.61, inGhost in the Atom (Cambridge Univ. Press. 1986)

[14] J. Wheeler, “Law without law” in Quantum Theory and Measurement,edited by J.A. Wheeler and Zurek (Princeton Univ. Press, 1983) p. 196

[15] J.S. Bell and M. Nauenberg, “The moral aspects of quantum mechan-ics,” in Preludes in Theoretical Physics, edited by A. De Shalit, HermanFeschbach, and Leon van Hove (North Holland, Amsterdam 1966), pp.279-286. Reprinted in J.S. Bell Speakable and Unspeakable in Quantum

Mechanics (Cambridge Univ. Press 1987) p. 22

[16] R.P. Feynman, R.B. Leighton and M Sands, The Feynman lectures on

Physics

vol. 3 (Addison Wesley, Reading 1965) 3-7

[17] R.P. Feynman, Theory of Fundamental Processes: Notes of Feynman’s1956 lectures at Cornell University taken by Peter Carruthers andMichael Nauenberg (Benjamin, New York 1961), pp 1-2

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[18] N.G. van Kampen, “ Ten theorems about quantum mechanical measure-ments” Physica A 153 97 (1988)

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